Comparison of Weed Extract from Asteraceae as the Insecticidal Growth Inhibition on Common Cutworm

Abstract

The objective of this study was comparison of weed extract from Asteraceae (Chromolaena odorata (L.) R.M. King & H. Rob), Ageratum conyzoides L. and Praxelis clematidea) as insecticidal activity and growth inhibition on the 4^th instar larvae of common cutworm, (Spodoptera litura). The leaf dipping method at various concentration of weed extract from Asteraceae 0, 0.5, 1.0, 2.0, 4.0 and 8.0% (w/v) were applied. Ten of the 4^th instar larvae were starved for 12 h and then released into the plastic box and were replicated for five times. The results found that the C. odorata extract as insecticidal activity and growth inhibition on the 4^th larvae of common cutworm was significantly effective (p<0.05). At 8% of C. odorata extract was effective as insecticidal activity on the 4^th larvae of common cutworm. The percent of mortality was the highest 100% and LC₅₀ was 1.41 at 24 h. The growth inhibition at 0.5% of the C. odorata extract, the percent of mortality of pupae was highest at 42% and the time of development of adult stage was 8.20 + 0.74 days. While the A. conyzoides and P. clematidea extract were 18 and 20% and 5.80 + 0.97 and 6.00 + 0.63 days, respectively. When the compare with control was non mortality. Therefore, Siam weed extract can use farmer’ s filed and safe for health human and environment.